EVALUATION OF SOME APPLE VARIETIES TO FIRE BLIGHT (ERWINIA AMYLOVORA) SUSCEPTIBILITY IN NATURAL FIELD CONDITIONS

Fire blight (Erwinia amylovora) is a very important disease that need to be carefully managed as it is classified as a ’’quarantine disease’’ and can spread itself very quickly when the conditions are favorable (presence of focus, high air humidity and high temperatures, presence of susceptible organs like flowers or long young twigs,..). The study was carried out at Research Institute forFruit Growing Pitesti, Genetic and Breeding Department, during 3 consecutive years (2010-2012), including 36 apple cultivars, old and newly bred. In this study, we present the response of the apple cultivars to fire blight attack, assessed in natural conditions of infection, range a large scale of variability, which denotes a strong influence of the genotype in expression of resistance or susceptibility to disease